Ubiquitous computing may be defined broadly as "machines that fit the human environment instead of forcing humans to enter theirs."

The "natural" interaction paradigm of ubiquitous computing has yet to emerge. Current human-computer interaction models, whether command-line, menu-driven, or GUI-based, are inappropriate and inadequate to "ubiquitous".

Yet in many ways we are already living in a ubiquitous computing world: Internet, mobile devices, GPS, digital audio players, radio-frequency identification tags, and interactive whiteboards is evidence of attempts to interact with humans in better ways.

Moreover, innovation is creating a more ubiquitous technology world every day. Recently, the invention of a thin and flexible electronic circuit that can be stuck to the skin like a temporary tattoo will soon allow us to wear our computer or mobile phone under our sleeve. See: http://ind.pn/rmkNwS

According to Stephen Hawking, "Humans are entering a stage of self-designed evolution." Consider the following examples: